Long range timing apparatus



Allg. 24, A. LOFT LONG RANGE TIMING APPARATUS Filed Nov. 17, 1953 lub las s l0 Inventor: Arne LoFt,

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/*lis Attorney.

Patented Aug. 24, 1954 LONG RANGE TIMING APPARATUS Arne Loft, Scotia, N.Y., assignor to General Electric Company, a corporation of New YorkApplication November 17, 1953, Serial No. 392,652

3 Claims. 1

This invention relates to timing devices, particularly to a combinationof timers arranged to provide an extremely wide range of intervals. i Inconnection with regulators for'gas turbine powerplants, it becamenecessary to provide timing apparatus having a range of adjustment froma few seconds up to many hundred hours, the total range of adjustmentbeing on the order of 5,000,000 to 1.

Accordingly, the purpose of the present invention is to provide improvedtiming apparatus having an extremely wide range of adjustment, and whichcan be assembled from standard components of inexpensive and reliableconstruction.

Other objects and advantages will become apparent from the followingdescription taken in connection with the accompanying drawings, in whichFigure l is a schematic representation of timing apparatus incorporatingthe invention, and

Figure 2 is a diagrammatic representation of the operating cycle of theapparatus.

Generally stated, the invention is practiced by connecting two standardtimers and a time delay relay in such a manner that one timer is causedto be repeatedly reset by the time delay relay, while the other timercounts the number of cycles through which the time delay relay hascaused the first timer to operate.

Referring now more particularly to Figure l, the invention makes use oftwo standard timing devices, shown diagrammatically at I and 2 and aconventional time delay relay 3.

The timers I and 2 are of substantially identical construction,therefore corresponding parts are represented by similar referencenumerals, distinguished by appropriate subscripts. The rst timing deviceI is adapted to run whenever energized, so as to accumulate a series ofidentical time intervals, and to perform some indicating or regulatingfunction at the end of a preselected time period. While many equivalentknown timing devices for performing this function may be employed, thetimer I is illustrated diagrammatically as comprising a reciprocableplunger member :t arranged to actuate a normally closed switch 4d and asecond normally closed switch 4b. Connected to the lower end of plunger4 is an automatic reset spring 5. A manual reset handle may also beprovided. Plunger 4 is retained in its lowermost position, with switches4d and ib closed, by mechanical latch 'I including a pivoted detent laengaging a projecting shoulder lb on the plunger 4. It will be observedthat the lower side of shoulder 'Ib defines a long sloping cam portionadapted to engage the curved upper end of detent 'Ia so as to push thedetent out of the way when plunger 4 descends in the resetting process,as described more particularly hereinafter.

Detent 'Ia is adapted to be engaged at the end of the preselected timeinterval by a tripping member in the form of a longitudinally travelingrack 8, which is of course supported in suitable guide members (notshown). Rack E is biased by spring 9 to an initial position determinedby the stop member I0. Rack 8 is adapted to be driven to the left, so asto trip detent 'ia after a preselected time interval, by a pinion Ildriven through a clutch I2 and suitable gearing I3 by an electric motorI4. In order to vary the time required for the rack 8 to engage detentic, the gearing may be of any suitable type of variable speed-changegearing, the ratio being selected by the manual lever I5.

rlhe timer I is conditioned for operation by means of a pivoted armatureIt actuated by a solenoid Il. As will be apparent from Figure armatureI6 is connected to plunger i by a tension spring I8,I and is alsoarranged to effect engagement of clutch I2 by means of the shift yokeI9. Energizing solenoid I'I causes armature I6 to rise, thus tensioningspring I8 and engaging clutch I2. When the rack 8 releases detent ia,the plunger 4 moves upwardly under the tension of spring I8, which isstreng enough to overcome the tension of the reset spring Vhen solenoidIl is (ie-energized, the weight of armature I5 and the tension of spring5 cause plunge.'

Y 4 to descend, whereupon the cam portion of shoulder 'Ib moves detent'la clockwise permitting the shoulder Ib to resume the latched positionillustrated in the drawing. Switches la and d?) are both closed whenplunger 4 is in the lowermost position; and both are open when theplunger is in the tripped or uppermost position.

The second timer 2 is of the same general type represented at I, butWith a few small differences. Instead of having adjustable ratio gearingas at I3, the gearing I3a is of a xed ratio type, and adjustment of thetime interval is effected by making the stop member Ia adjustable insome suitable manner. In Figure l, stop ita is represented as anadjusting screw which can be positioned so as to determine the length oftravel of the rack 8a before it engages detent lc. This is of course asimple mechanical equivalent of the adjustable ratio gearing I3.Furthermore, the switch 4d is normally closed and the switch 4e normallyopen when plunger 4c is in the lowermost latched position. When plunger4c moves upwardly, switch 4e closes and switch 4d opens.

The time delay relay 3 is represented as comprising a plunger member 2liarranged to close a switch 2| when in the lowermost or inactive positionas illustrated in Fig. 1, and to maintain a second switch 22 closedthroughout the duration of each operating cycle of the time delay relay.To this end, the switch 22 may comprise a pair of elongated contactstrips 22a which are ridged by the moving member 22h throughout thestroke of plunger 2li, the switch 22 being normally open when theplunger is in the lowermost or inactive position shown. Plunger 2Q isbiased to its inactive position by a tension spring 23 and elevatedagainst the tension of that spring by a solenoid 2li. An adjustable timedelay is provided by the pneumatic dashpot 25, illustrated as comprisinga cylinder 25a containing a piston 25D. Instantaneous upward movement ofpiston 25h is permitted by a pair of ilapper valves 25C, 25d, both ofwhich open when the piston moves upwardly. Conversely, both flappervalves close when the piston starts downwardly, and the rate of downwardmovement of plunger 2@ is regulated by adjusting the air escape vent i5@by means of the thumbscrew 25j. It will be obvious that any equivalenttime delay device may -be employed.

As will be apparent from the drawings, switch 2l is normally closed,when the relay 3 is inactive, but remains open during the entireoperating cycle of the time delay relay, while switch 22 is normallyopen but remains closed throughout the operating cycle of the relay. y

An important advantage of the present invention lies in the fact that itprovides an extremely wide range timing apparatus readily assembled fromtwo conventional timers l, 2 of types well known to the prior art, and astandard time de lay relay 3 which may be of any of numerous knowntypes. The timers l and 2 may, for instance, be adjustable for timeintervals from three seconds to thirty-three minutes, and the time delayrelay may be adjustable for intervals from one-quarter second to threeseconds. As will be seen hereinafter, the cumulative timer l isordinarily set for a comparatively long interval, the interval timer 2is set for a shorter interval, and the time delay relay has a stillshorter operating cycle. Specifically, the timer i may be set for 3ominutes, the interval timer 2 may be set for l0 minutes, and the relay 3may be set for 3 seconds, giving a total time of 30 mintues timesminutes over 3 seconds or 6,000 minutes, or 10G hours.

The interconnections by which these standard components produce the longrange timing function are as follows:

The external power supply circuit 26 energizes solenoid il when switch2l is closed. This of course attracts armature iii and conditions timerl by tensioning spring i8 and engaging clutch l2. It will be seen inFigure l that the power supply to motor It is by way of conductors 28,2Q, 33, 30, including the normally closed switch 4b and the normallyopen switch 22. lt will be apparent that motor i4 does not begin to runeven though switch ib is closed, since the switch 22 is open.

The switch lla associated with plunger Il performs the ultimatesignalling or regulating function, symbolized by the signal light 3l.Plunger 4 could of course be provided with other switches or equivalentdevices for initiating other signalling or regulating functions.

The power supply circuit for the other timer motor lila includes theconductor d, switch 4b, conductors 32, 33, normally closed switch 2 I,conductor 34, normally closed switch dd, and conductors 35, lill. Itwill be apparent that solenoid llo is connected across conductors 3d, 3oso as to be in parallel with motor ltd.

The energizing circuit for solenoid 2e of the time delay relay 3comprises conductor 28, switch lib, conductors 52, 35, normally openswitch 4e, and conductors 3l, 3d, Se. It is to be noted that the timedelay relay solenoid 13 is energized when plunger @c oi the intervaltimer 2 is tripped to its uppermost position. IThe supply of energy tosolenoid 2t causes plunger lo to immediately rise, which opens switch 2ito rie-energize solenoid ll'a of the interval timer This permitsarmature lea to drop, s o that plunger llc is reset by spring lia to thelatched condition shown in Figure l, in which the supply of energy tosole'- noid il is interrupted. Thus, it will be apparent that each timethe interval timer 2 trips plunger c at the end of an operating cycle,the switch lle momentarily energizes solenoid 2d so as to raise plunger2e and initiate the operating cycle of time delay relay which in turnre-sets the timer 2.

It remains to note that motor lt!- cr the cumulative timer i isenergized by switch 22 of the time delay relay throughout the durationof each operating cycle of the relay. Since solenoid Il of thecumulative timer i is continuously energized as long as the timingapparatus is operating, solenoid will remain in its uppermost position,with clutch l2 continuously engaged, so that timer l runsintermittently, and without resetting, during each operating cycle ofthe time delay relay It.

Timer l is reset either by momentarily opening switch 2l, or by forcingplunger Il downwardly by the manual reset handle t.

The integrated operation of the timing apparatus may be stated brieflyas iollows (l) the interval timer 2 goes through repeated cycles, beingreset at the end of each cycle by the time delay relay 3; 2) in additionto resetting the interval timer 2, the til. e delay relay 3 serves toenergize the cumulative timer l throughout each operating cycle of thetime delay relay; (3) the cumulative timer i adds up the length ofsuccessive operating cycles of the time delay relay 3, thus in effectcounting the number of cycles through which interval timer 2 hasoperated.

From this description of the operation it will be apparent that thelength of each operating cycle is equal to the time interval ti forwhich timer 2 is set, plus the length td of the operating cycle of thetime delay relay 3, while the number of elapsed cycles is represented bythe time te accumulated on the cumulative timer l divided by the lengthtd of the opertaing cycle of the time delay relay t. Therefore, thetotal elapsed time T, represented by the length of time the signal light.Si is on, may be represented by the expression 3 seconds to 33 minutesand time delay relay 3 having a range of from 1/.1 to 3 seconds, it canbe shown that the possible range of values forv the elapsed time T isfrom 6 seconds to 4400 hours, or a range of over 2,500,000 to l. Thus,the invention provides timing apparatus having tremendous latitude ofadjustment.

The functioning of the apparatus described above may be representeddiagrammatically as in Figure 2. The abscissa represents the totalelapsed time T. The lowermost curve represents the on and off cycles ofthe interval tmier 2. The middle curve represents the on and 01T cyclesof the time delay relay 3. And the upper curve represents the cumulativereading of the timer I. It will be seen that the cumulative timer I andthe time delay relay are both in the off condition while the intervaltimer 2 runs through its iirst cycle ti. When timer 2 trips, the timedelay relay 3 goes through its preselected operating cycle, during whichperiod td the cumulative timer I runs. At the end oi the short cycle oftime delay relay 3, timer I stops and the interval timer 2 starts asecond cycle. At the end of the cycle of timer 2, the time delay relay 3is again energized and the timer I runs. This process repeats untilcumulative timer I reaches the limit `of its preselected setting, atwhich time it trips to extinguish the sigf nal light 3 I, thusindicating the end of the total preselected interval T.

It is to be understood that the details of the timers I and 2 and of thetime delay relay 3 do not in themselves form a part of the invention, myinvention lying in the manner in which such standard timers and relaysmay be interconnected to achieve a timing function of enormous latitudenot possible with any timing apparatus available previously. Theinvention has the great advantage of utilizing inexpensive and reliablecomponents which are readily available and easily interconnected toperform the wide range timing function required. Timers and relays oiother mechanical, hydraulic, or electrical e types could be employed inplace of those shown in the drawings, so long as they are capable ofperforming the functions described for the cumulative or counting timerI, interval timer 2, and re-setting relay 3.

It is of course intended to cover by the appended claims all suchmodifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent oi the UnitedStates is:

1. Long range timing apparatus comprising a first motor drivencumulative timer adapted to signal the end of a iirst preset timeinterval, a. second motor driven interval timer adapted to signal theend of a second preset time interval, a time delay relay having anoperating cycle of a shorter third time interval, means for energizingthe i-lrst timer during each operating cycle of the time delay relay,means for energizing the second timer Whenever the time delay relay isin inactive condition, and means for initiating the operating cycle ofthe time delay relay each time the second timer reaches the end of saidsecond time interval, whereby said iirst timer accumulates intervalsrepresenting the sum of successive operating cycles of the time delayrelay.

2. Long range timing apparatus comprising a first motor drivencumulative timer adapted to run without resetting each time it isenergized and adapted to signal the end of a rst predetermined timeinterval, a second motor driven interval timer adapted each time it isenergized to run through an operating cycle of a second predeterminedinterval and then stop, a time delay relay having an operating cycle ofa third predetermined time interval, means connecting the time delayrelay to the second timer to initiate the operating cycle thereof at theend of the operating cycle of the time delay relay, means connecting thetime delay relay with said first timer for causing it to run during theoperating cycle of the time delay relay, and means associated with thesecond timer for initiating the operating cycle of the time delay relayeach time the second timer reaches the end of its operating cycle,whereby said time delay relay causes the second timer to executerepeated cycles and the first timer accumulates intervals representingthe aggregate operating time of the time delay relay.

3. Long range timing apparatus comprising a iirst cumulative timerhaving a motor, a plunger member, latch means for holding the plunger inset condition and a trip member driven by the motor and adapted torelease said latch after a i'lrst preselected time interval, a secondinterval timer comprising a second motor, a second plunger member, asecond latch member adapted to hold said second plunger member in setcondition and a second trip member adapted to be driven by said secondmotor to release the second latch after a preselected second timeinterval, and a time delay relay comprising a third plunger member witha solenoid adapted to move the third plunger away from its initialposition when the solenoid is energized momentarily, the time delayrelay having also means for returning the third plunger member to itsinitial position after a third preselected time interval, meansconnecting the time delay relay to the cumulative timer for energizingthe motor thereof during each time delay interval of the relay, meansconnecting the time delay relay to the second interval timer forenergizing the motor thereof to initiate the operating cycle of saidsecond timer, and means connecting said second timer with the time delayrelay for energizing the solenoid thereof each time the second timerreaches the end of its operating cycle, whereby the time delay relayresets the second interval timer each time it reaches the end of itsoperating cycle, the time delay relay also energizing the motor of thecumulative timer throughout each operating cycle of the time delayrelay.

References Cited in the iile of this patent UNITED STATES PATENTS NumberName Date 1,775,730 McNicol Sept. 16, 1930 2,254,795 Daniels Sept. 2,1941 2,290,626 Bosomworth July 21, 1942 2,637,835 Davidson May 5, 1953

